House Speaker Paul D. Ryan (R-Wis.) at the Republican National Convention. (TANNEN MAURY/European Pressphoto Agency)

At a gathering of the Koch brothers donor network, House Speaker Paul D. Ryan (R-Wis.) reportedly said, “We have to do a better job of taking the moral high ground . . . showing [conservative] ideas in practice.” Of the House Republicans, he said that “we also see ourselves adding a keel and a rudder to the ship, giving it substance and giving it direction. Giving it a moral foundation.”

You don’t know whether to laugh or cry. As well-meaning and as dedicated to conservative policy ideas as Ryan may be, he is deceiving himself. One cannot take the moral high ground when supporting Donald Trump for president. Ryan has all sorts of plans for tax reform, entitlement reform, fighting poverty, and foreign relations. Trump is not interested in or actively opposes many of them. That poses a nearly insurmountable hurdle for Ryan.

You cannot tell the poor you are concerned about them and also support the man who says you cannot be rich without being wealthy or who has stiffed and swindled working people all his life.

You cannot tell voters you are interested in sane and sensible immigration reform but then support someone who wants to round up and expel 11 million to 12 million people — and then force Mexico to build a wall.

You cannot tell voters you are for raising the age for Social Security and moving to a premium support Medicare plan while you bolster a candidate who says all we need to do is cut waste, fraud and abuse.

You cannot be for restraining the executive branch’s overreach and also be for a candidate who has no sense of restraint and thinks he can order the military to commit war crimes.

But the problem is deeper than a list (albeit a really long list) of fundamental policy differences. Ryan is arguing that Republicans are decent people who care for their fellow citizens and understand the serious requirements of good government. The most immediate way to demonstrate that would be to cast off Trump, who is devoid of decency, cares only about himself and is disdainful of learning anything needed for governance.

Conservatism has long held that a virtuous citizenry is needed for democracy to function. That does not mean our leaders have to be angels; the founders understood they were not. It does, however, mean that we require leaders who set the example for civil public discourse, self-discipline and respect for others — the whole slew of values required for self-government. Trump makes a mockery of all that. He does not aspire to civility, decency, self-discipline, etc. Republicans cannot hold the moral high ground while backing a despicable character like Trump.

In short, there is barely, if any, policy overlap between Trump and Ryan, but, more important, Trump is so defective as a person as to make any agenda impossible to carry out. The Khan episode, like the Judge Gonzalo Curiel, episode, is not about a policy or position; it’s about Trump’s character. In saying that doesn’t matter — and only the likelihood of achieving a plank of his platform does — Ryan makes a fundamental error. By repudiating of all the public virtues needed, whatever your agenda, Trump would lay waste to democratic governance itself. When Trump begins telling us the election itself is “rigged” — his built-in excuse for losing — he is undermining the legitimacy of our democratic process. You would think that at least should rouse Republican leaders.

The Post reports on signs that the episode with the Khan’s is different from previous Trump outbursts because the Khans are regular, real people — not judges, politicians, faceless immigrants, etc. That may be, although it is a sad commentary on the American people that one has to insult the parents of a dead war hero to trip the decency alarm. It has been impossible, it seems, for many Americans to empathize viscerally with POWs or women or any number of other groups he has attacked. But now that the public seems to grasp the depths of Trump’s depravity, Ryan and others can no longer treat his character as irrelevant. If they cannot lead the voters, perhaps they can at least follow them in pulling their support for Trump, citing his manifest cruelty and unfitness for office. That would not give House Republicans the moral high ground, but it would provide an escape hatch.